I have read on this site as well as other sites that the pitching in the Major Leagues is better now then ever before, and thus the offensive run production is down.
I believe there are a few things causing this shift.
PITCHING
1. Pitchers are throwing harder than ever before. There is no denying that at all. They have more pitches in their repertoires and it is much more difficult for hitters to identify those pitches. It use to be a starter had a four seam, perhaps a two seam with a little movement, either a curve or a slider (rarely did a pitcher have both) and a straight change. Now, the starters generally throw in a cutter, some have splitters, so on and so forth.
With the higher velocity, there is less reaction time.
2. Relievers now are better than ever before. It use to be that most relievers were just older starters that could not get the job done. However, nearly every team is taking some of their incredibly talented throwers from the minors and putting them in the pens. ie Chapman. In years past those pitchers would have been starters through and through...
DEFENSE
The scouting reports, defensive shifts, and better athletes in the field.
OFFENSIVE PHILOSOPHY
Here is one big thing. Now, I base this solely on my own playing experience, so bear with me. I have counted and throughout my high school and college career I played against 6 future major league pitchers (that I know of--there were a couple in national tournaments that I thought were great pitchers, I just forgot their names over the course of 20 years).
Now a few of us could hit these stud pitchers, but there was a different approach we had to take with them. We did not want to fall behind in the count to them. Bottom line. See the ball and hit it early in the count. Get a decent fastball and go. If we got into the hole with two strikes... YIKES.
The major point I am making is this.... with Moneyball and sabermetrics...and the focus on working a high pitch count and walks for a better on-base average. IF there is an organizational emphasis/ league-wide philosophy on seeing as many pitches, you are putting hitters in compromising positions from the start.
Just in my limited experience, I never felt comfortable with two strikes (even against lesser competition), but that was just my approach. I wanted to get the at bat finished before two-strikes.
At first glance, I loved the late 90's and early 00's Yankees teams because many of them were experienced/talented enough to work a deep count and get the starters out by the sixth--but those were some great ballplayers in NY.
But now... I think for MOST teams, getting to the bullpen is not all that rewarding. (Obviously you have some lesser teams in the MLB that just have horrific relievers, but for the most part those reliever are coming in and throwing 90+ and making life difficult with not only right-handed but left handed specialists...etc.
The bottom line is this. If you are focused on working a pitcher...and seeing as many pitches as possible, and that pitcher is of equal or better talent than you are--then it is my belief that you are playing right into their hands. These starters are now conditioned for a couple of things.
1. Pitch 6 innings of three runs or less.
2. Knowledge that the hitter/team is looking to work the count and take a walk.
3. Greater emphasis on get ahead stay ahead. (Obviously this is age-old BUT now, knowing that hitters are being conditioned to see more pitches, I have seen more first pitch fastballs getting middle-out than in A LONG TIME.)
I think a team of hitters that can still be effective taking pitches and working a count will create a decent ball club--but bear in mind... most of those hitters are either veterans or just really good baseball players.